A new global assessment of forests - perhaps the largest terrestrial repositories of biodiversity - suggests that, on average, a 10% loss in biodiversity leads to a 2 to 3% loss in the productivity, including biomass, that forests can offer. Based on these results, the authors estimate the value of biodiversity in maintaining commercial productivity to be 166 to 490 billion (USD), which would be considerably greater than the total cost of effective global conservation. The results could be used to better inform forest management and restoration. The biodiversity-productivity relationship (BPR) has gained the interest of scientists and policy-makers over recent years, but most BPR assessments of forests have been regional to date. To gain more insights into BPR on a global scale, Jingjing Liang et al compiled data from 777,126 sample plots across 44 countries and 13 ecoregions. In total, more than 30 million trees across 8,737 species were tallied and measured. Their assessment reveals that, in general, on a global scale, a 10% decrease in tree species richness would cause a 2 to 3% decline in productivity, which is the rate of biomass production in an ecosystem. A 99% decrease in tree species richness, by contrast, results in productivity declines of 62 to 78%. While productivity trends consistently decrease with increased biodiversity loss across nearly all regions of the world, the areas that would experience the greatest productivity decline in absolute terms include the Amazon, West Africa's Gulf of Guinea, Southeastern Africa, Southern China, Myanmar, Nepal, and the Malay Archipelago.